Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/16/22
Area Forecast Discussion
National Weather Service Denver/Boulder CO
815 PM MST Sat Jan 15 2022
.UPDATE...
Issued at 803 PM MST Sat Jan 15 2022
West/northwest winds are managing to penetrate into a few areas
adjacent to the foothills, mainly around Rocky Flats. The HRRR has
done the best job of depicting that this evening, so have blended
it into the forecast and bumped minimum temperatures upwards for
tonight for those areas where winds should remain breezier.
Otherwise, no notable forecast changes this evening. Front still
looks on track for tomorrow, with main impact being some enhanced
north and northeast winds for the plains from mid morning into the
afternoon.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 1258 PM MST Sat Jan 15 2022
Quiet weather continues this evening through Sunday under the
influence of dry northwest flow. Winds will pick up quite a bit
tonight across the high country, especially above 9,000 ft and
east of the Divide. The direction is not great for mountain wave
development as it will be out of the northwest. There is a weak
stable layer above ridgetop tonight, and with weak synoptic
subsidence it looks like the winds may make it down to around 6,000
ft elevation at the base of the foothills, but probably no
further than that. In general, expect gusts in the 40-50 mph range
in the higher elevations and eastern foothills, maybe 25-40 mph
across the base of the foothills, and not much wind at all along
and east of I-25. The downslope winds should decrease by mid
morning Sunday. Temperatures tonight will be warmer than last
night with lows in the 20s across the plains (30s in the lower
eastern foothills), and teens in the cold valley spots in Weld
County. The mountain valleys will also be not as cold, with lows
in the single digits and teens in North and South Parks. Middle
Park once again will be coldest, with lows near 0 degF though in
the Fraser River valley it could again drop to around
-10 degF.
Sunday will be another nice day and dry. The winds in the
foothills and mountains will be weaker by midday, but across the
plains a weak cold front will move south during the late morning
hours bringing with it north winds gusting 20-35 mph, especially
east of a Fort Morgan to Limon line. Though it`s indeed a cold
front, with full sun and mechanical mixing, today`s inversion will
be wiped out resulting in a net warming vs today. Expect highs in
the upper 40s to low 50s across the plains. 700 mb temps remain
fairly warm despite the northwest flow (0 - +2 degC) so the
mountain valleys should see highs in the 30s to near 40.
.LONG TERM...(Sunday night through Saturday)
Issued at 1258 PM MST Sat Jan 15 2022
We`ll end the weekend with quiet weather and fairly mild lows
across the urban corridor and foothills. The exceptions will be
the lower elevations in Middle Park where lows below zero will
still be likely.
Monday is expected to be the warmest day of the week, with mild
temperatures across the forecast area. Temperatures should warm up
into the mid to upper 50s across most of the plains. There is some
mid/high-level moisture around and cloud cover could limit our
warming potential a little.
Tuesday will stay fairly mild before a cold front approaches late
Tuesday or early Wednesday. Guidance diverges by the middle of the
week. An upper ridge should develop off the Pacific coast with a
deep trough settling over the east. The main question will be how
far west the longwave trough extends and how much moisture will be
available as a couple shortwaves push across the region. The
ECM/GEM are a bit more aggressive with cold air pushing into the
forecast area while the GFS is warmer/drier. Will maintain just
slight chances of PoPs for the second half of the week until
guidance comes into better agreement. Either way, any snow that
falls will be fairly light.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 803 PM MST Sat Jan 15 2022
VFR and no precipitation through Sunday. Drainage flow 9-13 kts will
continue through Sunday morning for all but KBJC where west winds
may prevail during the overnight hours. On Sunday, winds are
expected to turn westerly in the morning ahead of another weak
cold front, which will shift winds to the north/northeast around
10 AM and may produce gusts of 20-25 kts for a few hours.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Rodriguez
SHORT TERM...Schlatter
LONG TERM...Hiris
AVIATION...Rodriguez
Area Forecast Discussion
National Weather Service Columbia SC
931 PM EST Sat Jan 15 2022
.SYNOPSIS...
Little change to the forecast for Sunday`s winter storm with
widespread freezing rain expected from Newberry through
Chesterfield counties. Greatest impacts will across the northern
Midlands and become less severe into the southern Midlands and
CSRA. For parts of the northern Midlands, this will potentially
be the most impactful ice event in several years. Windy
conditions are also expected tonight into Sunday and again
Monday. High pressure along with cool and dry air will produce a
more typical January pattern through midweek.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Update...
Fairly minor tweak to tonight`s forecast. Latest HRRR and some
other guidance indicating a period of light snow changing to
sleet possible for a few hours at the onset before the
changeover to freezing rain, mainly across northern portions of
the far northern Midlands, with accums one half to near one inch
possible, around 06z-08z.
Otherwise...
Increasing mid and high level cloud cover with mostly virga at
0230z, with some -ra at AGS. Upper and surface low pressure to
our west will move east tonight and spread warm moist air from
the Gulf of Mexico up into our region above the surface. At the
surface, high pressure centered over New England to direct cool
dry air down into our region. Moisture falling into cool dry air
will lead to evaporative cooling with surface temps falling to
near or below freezing for much of the FA, causing freezing rain
to develop. Although there could be some light snow or sleet at
the onset of precipitation, rain changing to freezing rain is
the main threat. Expect ice accumulations to begin late
tonight, mainly northern and central areas. Winds will also
increase as the surface low nears, and a lake wind adv is in
effect starting at midnight.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Low pressure will march from western Ga through the southern
Midlands during the day Sunday then offshore of NC Sunday
evening. With the cold air in place the combination of freezing
rain and rain will continue Sunday morning then begin retreating
northward as temperatures warm slightly through the day. Several
concerns remain surrounding the change from freezing rain to
rain however confidence in the change back to rain is
increasing. Pwat values will be well above normal for January
with values pushing 1.1 inches during the morning and rainfall
intensity expected to be moderate. This will help to hold
temperatures up slightly in the eastern Midlands through the
southern CSRA however with the wedge slow to erode temperatures
in the warning area will creep above freezing between midday and
the early afternoon hours however afternoon highs will only be
in the upper 30s across the western Midlands through the Pee
Dee. This will keep freezing rain in those areas through early
afternoon with ice accumulations through the day around one
quarter of an inch. With the wind gusts continuing up to 30 mph
into the afternoon ice which accumulates will continue causing
issues with trees and power lines.
Concern continues into Sunday night as the low begins departing
the region and colder air moves in. Although moisture will be
moving east of the area there will be some remaining rain and
there is potential for some rain to mix with with a few flakes
of snow through midnight across the northern and western
Midlands. No accumulation is expected. As the temperatures drop
to or below freezing wet surfaces and roads will begin freezing
causing hazardous travel to become increasingly hazardous
through daybreak as temperatures continue falling. Overnight
lows will be in the upper 20s in the northern and western
Midlands with near freezing elsewhere.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
A strong cold advection regime will develop behind the system
for Monday, with gusty west winds up to 30 mph. Consequently
high temps will remain in the 40`s Monday afternoon. The
pressure gradient should weaken enough Monday night into Tuesday
to allow for good radiational cooling, coupled with some weak
cold advection, to drop temps well into the 20`s. Good agreement
across guidance for fairly zonal flow aloft and weak surface
ridging through mid-week, so temps should generally remain below
average with little precip chance through early Thursday. The
long term becomes much more interesting starting Thursday as a
deep trough with diving shortwave along its western edge swing
into the Central US. Rain will be likely with the initial
frontal passage Thursday before the diving shortwave beings to
swing around the primary trough axis. This setup is relatively
well agreed upon across global ensembles and operational
members. Obviously we are way too far out to begin discussing
specifics, but the overall pattern and trend requires close
monitoring.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Mostly VFR conditions are anticipated at all terminals through
this evening ahead of the next storm system. Conditions are
expected to deteriorate after 03-06Z as ceilings lower and
showers developing will lower cloud bases. MVFR conditions are
expected to develop by 06-08Z while showers increase in coverage
and become a steadier rain, saturating the low levels. Ceilings
at all terminals are expected to degrade to IFR at times after
08-10Z across the board. Precipitation should be mostly rain on
Sunday for OGB/AGS/DNL though a brief period of freezing rain
cannot be ruled out in the morning. This has been omitted from
the TAFs due to lack of confidence. Temperatures are expected to
be cold enough at the surface for CAE/CUB to see several hours
of freezing rain Sunday morning and is indicated in their TAFs.
A strong low-level jet associated with this storm system is is
evident on expected to develop late tonight and has the
potential to create significant wind shear at all terminals on
Sunday. Winds at the surface will initially start light but will
increase towards daybreak, especially at OGB/AGS/DNL where
gusts have been added to the forecasts.
EXTENDED AVIATION OUTLOOK...Conditions improve for Monday though
it will be breezy at times with LLWS possible early. The next
chance for restrictions is expected with a cold front Wednesday
night into Thursday.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...Lake Wind Advisory until 4 PM EST Sunday for GAZ040-063>065-
077.
Winter Weather Advisory until 4 PM EST Sunday for GAZ040-
063>065.
SC...Lake Wind Advisory until 4 PM EST Sunday for SCZ016-018-
020>022-025>031-035-037-038-041-115-116-135>137.
Winter Weather Advisory until 4 PM EST Sunday for SCZ018-
025>031-037-038-135-136.
Ice Storm Warning until 1 AM EST Monday for SCZ016-020>022-115-
116.
&&
$$
Area Forecast Discussion
National Weather Service Des Moines IA
529 PM CST Sat Jan 15 2022
...Updated for the 00z Aviation Discussion...
.DISCUSSION.../Tonight through Saturday/
Issued at 316 PM CST Sat Jan 15 2022
Primary messaging highlights:
* Cold, with low clouds and some fog possible tonight
* Light mix chances northeast late Sunday
* Another shot of arctic cold midweek
Our overall weather pattern isn`t going to change a whole lot
through the period with varied degrees of northwest flow keeping
our temperature regime near normal to below normal and only a few
windows of precipitation possible. Iowa is between systems right
now with cold surface high pressure from Nebraska into the Great
Lakes. This should settle into the state tonight, and with fresh
snow cover have dropped lows to the lower end of guidance with a
least a period of favorable radiational cooling conditions.
Confidence in the degree of cooling is not great however, with the
high`s passage and weak return flow starting overnight, and the
possible expansion of stratus lingering over parts of west central
and southern Iowa this afternoon. There may also be a period of
patchy fog coincident with the stratus and boundary layer cooling.
The attention by tomorrow will turn to what is really the only
precip concern at the moment as PV anomalies across the western
Canadian provinces reaching the Great Lakes and eventually Iowa
early Sunday evening. Forcing will increase ahead of these
features tomorrow with Iowa on the southwest fringe of QG forcing.
Confidence in the sensible weather response to this lift is low
however with soundings suggesting difficulty phasing moisture of
any sufficient depth. Model soundings do depict ice introduction
at times, but also suggest periods with a dry layer between that
and better low level moisture. This leaves periods of light snow
and light freezing rain/drizzle both in play. The guidance spread
in QPF is also noted with the EC and GFS and associated ensembles
mainly dry, while recent HRRR and RAP runs point toward more
appreciable amounts. Some high res guidance also depicts shallow
convection may follow the surface trough passage, with continued
precip type uncertainties.
Regardless of how this eventually plays out, the precip should
exit by the end of the weekend and to start the work week with the
primary weather theme being another period of bitter cold
temperatures by midweek. Monday and Tuesday will be mild with
normal to slightly above normal temperatures before a sharp cold
front Tuesday evening. This will bring a period of gusty winds
into Wednesday morning before an arctic high settles into Iowa
Thursday Night. Temperatures will drop from the frontal passage
into this resulting in lows well below zero Wednesday and Thursday
Nights, and highs no better than either side of zero north
Thursday. This will result in a prolonged period where wind chill
headlines seem likely across at least part of the forecast area
Wednesday Night into early Thursday, and again Thursday Night into
early Friday. There are a few windows of light precip possible to
end the forecast period from this cold episode into the next
weekend, but nothing sufficient to introduce chances at this
point.
&&
.AVIATION.../For the 00Z TAFS through 00Z Sunday evening/
Issued at 525 PM CST Sat Jan 15 2022
Stratus expansion and possible fog development are the two
aviation forecast challenges tonight. MVFR stratus continues to
blanket portions of southern Iowa. Model guidance suggest this
will slowly expand northward tonight. Tempo IFR cigs are possible.
Fog development also appears likely, but the spatial extent and
degree of visby reduction is difficult to pinpoint at this time.
A return to VFR is anticipated for most terminals Sunday morning,
but the stratus may linger in southern Iowa including KOTM. A
passing system will bring more low cloud cover and possibly some
precip to north central Iowa after 18z, however no precipitation
was mentioned in the TAF at this time.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Small
AVIATION...Martin
Area Forecast Discussion
National Weather Service Goodland KS
355 PM MST Sat Jan 15 2022
.SHORT TERM...(This evening through Tuesday Morning)
Issued at 228 PM MST Sat Jan 15 2022
Latest visible satellite analysis and RAP analysis indicates the
High Plains in between a departing (eastward) moving low and lee
troughing developing over the northern High Plains. High
temperature forecast remains on track with afternoon highs ranging
from the upper 20s/low 30s to upper 30s, with the cooler
temperatures over the eastern CWA which had high clouds linger
longer from the departing eastern Kansas storm system.
Tonight, mid to high clouds overspread the area from the above
mentioned trough as winds become more southwesterly around 10 knots.
Overnight low temperatures look to fall into the mid teens to lower
20s over the area, with locally lower temperatures in low lying
areas.
Tomorrow and Monday will be noticeably warmer with above normal
temperatures returning due to WAA as high pressure system over the
northern Rockies develops. Temperatures will range from the low-mid
50s to low 60s over the Tri-State area. Its not very often,
especially in Goodland, for 20 to 30 degree warming swings to
occur in January. Looking at the past 5 years in January, this
occurrence does happen sporadically especially coming out of a
cold snap. Winds will be northwesterly tomorrow and breezy as
sustained winds of 10-20 knots and gusts of 25-30 knots will be
expected. Monday will be similar for the magnitude, however winds
will be from the southwest. Elevated fire weather conditions will
be expected tomorrow as RH values fall into the upper teens to
low 20s. Monday will have the potential to see near critical fire
weather conditions as the southwesterly winds will bring in
slightly drier air as RH values along and west of Kansas Highway
27 fall into the mid teens. Uncertainty does lie with how dry the
air will become as some more moist air is forecast to located
along and south of Central Arizona into Central New Mexico, so the
question will be will any of that more moist air be advected into
the High Plains with southwesterly winds. Overnight lows Sunday
and Monday night will be in the low to mid 20s.
.LONG TERM...(Tuesday through Saturday)
Issued at 225 PM MST Sat Jan 15 2022
Tue-Wed: Expect dry conditions and an abrupt transition from
above normal temps (Tue) to below normal temps (Wed) -- as the
synoptic pattern over the central CONUS abruptly transitions from
NW flow => cyclonic flow aloft.. and a Canadian/Arctic airmass
surges southward along the lee of the Northern/Central Rockies..
the leading edge of which will manifest as a pronounced cold
frontal passage /northerly wind shift/ late Tue aft/eve. At this
time.. northerly winds are not anticipated to exceed 25-35 knots.
Thu-Sat: Guidance suggests that cyclonic flow aloft will
transition to northerly flow aloft late next week.. as an
amplifying upper level ridge along the Pacific Coast migrates
inland over the Intermountain West. Given that the synoptic
pattern is progged to be in a state of transition/amplification --
and that the High Plains will be situated on (or very near) an
inflection point -- confidence in sensible weather conditions is
well-below average.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 354 PM MST Sat Jan 15 2022
VFR conditions are expected to persist through this TAF period at
each site. Southerly winds will slowly turn westerly overnight
before becoming northwesterly late morning Sunday. Winds will become
sustained at 10-20 knots with gusts up to 30 knots expected
throughout the afternoon Sunday. Winds will then return westerly to
end the TAF period around 10 knots. Scattered areas of mid to high
clouds return overnight tonight and throughout the day tomorrow
before clearing out around towards the end of the period.
Forecast soundings indicate a period of LLWS at each site, with KGLD
starting around 08Z and lasting through 14Z. KMCK can look to
begin around 06Z and lasting through 16Z.&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...TT
LONG TERM...VINCENT
AVIATION...TT
Area Forecast Discussion
National Weather Service Jackson MS
948 PM CST Sat Jan 15 2022
...WINTER WEATHER LIKELY TONIGHT INTO SUNDAY MORNING...
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Storm system moving over the region, and only light precipitation
so far behind the front. BR/-RA and a snowflake or two make up
the bulk of the reports under any echoes on radar. Areas further
to the NW, into SErn AR and NW LA getting a dusting, if only
briefly. Models have actually trended down somewhat in the highest
snowfall amounts with the elongated sfc low/trough to the east
and a positive tilt to the upper low resulting in a little less of
a classic trowal situation...at least for most of the area.
Highest amounts still shunted well north of JAN forecast
area...though the extreme NW, Sunflower and Bolivar Counties are
on the edge of potentially higher totals up to 2 inches. That
being said, the wrap around precip on the back edge of this storm
is still rather prominent and extending a little further southward
into the morning hours. The earlier extension of the Winter
Weather Advisory continues to look like a good place to see
accumulating snow. So far, the forecast is well on track and do
not see any evidence to sway from the current trends.
Prior discussion below:
Tonight & Sunday...
Tonight-Sun: Main focus remains on winter weather event likely Sun.
At the start, cold core will continue diving to the E-SE, with
center of cold core currently centered over the ArkLaTex this Sat
aftn & MS River to I-55 corridor by midnight tonight. This highly
dynamic system is progged to bring strong TROWL & wrap around
moisture, broad sfc low pressure/baroclinic zone centered off to the
E-SE into Sun. Increasing isentropic ascent/convergence into strong
deformation zone & conditional symmetric instability (CSI) will be
present, along with good frontogenesis. Strong ascent will keep
broad deformation axis of rain changing over to snow generally along
& W of MS River by 9PM-midnight, along & W of I-55 before daybreak &
E of I-55 through Sun aftn, with some lingering light snow into
early Sun aftn. There continues to remain lowered confidence on how
much low-level thermal warmth near the sfc will remain & how much
that TROWL will keep rain lingering longer & any potential
limitations on efficient moisture in the snow growth region. The
upper cold core & low-mid level low position remains right along or
just a touch S of I-20, which is slightly further N of a memorable
cold core/winter event in Dec 1997. Some areas along the Natchez
Trace & SE could have potential for some low-level BL WAA & rain
lingering longer. Regardless, when it switches over, limited melting
& some quick lapse rates could keep it just rain/snow & less precip
type issues. If the switchover is slow & dynamic cooling/lift &
saturation through snow growth region is somewhat less, this could
keep rain around longer, limit snow accum totals/impacts & bring
some brief freezing drizzle potential. There remains enough
confidence that areas in the N-N central MS, far NE LA & SE AR
remains likely for accumulating snow & some potential of some
approaching or possibly exceeding winter storm criteria, especially
into N Bolivar C. HRRR has continued some back & forth of low-level
warmth/TROWL issues with less totals along & E of the Natchez Trace,
but some mesoscale features that induce localized higher totals in
these areas. 12Z runs indicate some higher end potential to possibly
exceed winter storm criteria, including HREF PMM. For now, with
limited probs > 2 inches into our NW, main adjustments were to
adjust the ongoing "Limited" graphic slightly further S & SE &
expand the ongoing Winter Weather Advisory a tier of counties S to
include Ashley Co in AR, N tier of parishes in LA & a tier to the E-
NE in MS. With limited area of exceeding winter storm criteria,
held off at this moment on any addition, but will be something to
monitor & potential remains. Any snow that falls & accums,
especially on elevated surfaces, including roads & bridges, could
keep slick conditions around through early Mon morn.
Lows that morning will only peak near or just above freezing, with
areas having best snowfall potential falling near the freezing mark
in the N-NW, while only climbing into the mid-upper 30s in the E.
Continued leaning towards raw blend of guid for highs. In addition,
TROWL situations & with strong gradient, efficient gradient winds
could approach 20-25mph sustained near wind advisory, with 35-35mph
gusts at times. In areas of heavier snow bands in NW Delta, just
before daybreak, this could bring visibilities down & create
additional travel difficulties. With potential for heavy wet snow at
times, some power outages could be possible as well, especially in
any heavy banding. A "Limited" gradient wind is out & made a small
expansion to the SW. Lastly, some areas in E-NE MS could see some
convective rain prior, with some QPF totals in excess of 1-1.5+
inches. For now, something to monitor but will hold off in the HWO.
/DC/
Sunday night through Friday night: Come Sunday evening the closed
low is expected to have shifted far enough to the east for the
precipitation to have ended over our eastern most zones. Wl still
have northwest flow aloft across our region and there will be a
shortwave within this flow swinging across the region but no
additional precipitation is expected with it in our CWA. Dry weather
is expected to continue through Tuesday night. Colder than normal
temperatures are expected Sunday night through Monday night but
temperatures will be back slightly warmer than normal Tuesday.
Tuesday wl be under near zonal flow aloft and a surface high will be
centered just east of Mississippi resulting in a light return flow
across our region. Moisture will increase slowly into Wednesday
morning over our area ahead of a cold front that will be dropping
into the central Plains Tuesday night. Models agree that a weak
surface low will be moving to the northeast from the Arklatex region
that may delay the cold front but rain and a few storms are expected
to develop along and ahead of the front across our CWA Wednesday.
Model differ on when the cold front will be southeast our CWA but
anafrontal precipitation is expected to end well before noon
Thursday. In the wake of the cold front a large >1040mg surface high
will build in from the northwest and bring in a much colder and
drier airmass. With the exception of our southeast, morning lows
will be back in the low to mid 20s. Models differ on the timing of a
potent shortwave that is expected to swing across our region Friday
but currently no precipitation is expected in our CWA. However, the
passage of the shortwave will help result in temperatures bottoming
out a couple degrees colder Saturday morning where low to mid 20s
are expected areawide. /22/
&&
.AVIATION...
00Z TAF discussion:
IFR in most locations...though a couple terminals holding on to
MVFR for now. Storm system on approach resulting in deteriorating
conditions and an eventual changeover from rain to a rain snow
mix, particularly along and north of HKS/JAN/MEI line. GLH/GWO/GTR
will become more snow dominant by 06z and continue through the
morning hours. Winds will be gusty in the overnight in proximity
to the low center.
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 33 39 33 54 / 53 21 0 0
Meridian 34 39 31 53 / 91 39 0 0
Vicksburg 33 44 33 56 / 48 10 0 0
Hattiesburg 33 40 32 57 / 72 6 0 0
Natchez 33 46 33 57 / 22 4 0 0
Greenville 32 43 33 52 / 81 16 0 0
Greenwood 33 38 31 50 / 87 46 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Winter Weather Advisory until noon CST Sunday for MSZ018-019-
025>027-034>036-040>042.
LA...Winter Weather Advisory until noon CST Sunday for LAZ007>009.
AR...Winter Weather Advisory until noon CST Sunday for ARZ074-075.
&&
$$
HJS
Area Forecast Discussion
National Weather Service Louisville KY
953 PM EST Sat Jan 15 2022
.Forecast Update...
Issued at 953 PM EST Sat Jan 15 2022
Mostly cloudy skies were noted across the region this evening.
Temperatures were in the upper 20s over portions of southern Indiana
and northern Kentucky. South of I-64 temps were in the lower 30s,
but rose to the mid 30s from the Cumberland Parkway and points
south. Area radars are quiet, though we do have some light
precipitation down along the KY/TN border that hasn`t moved all that
much northward this evening.
Early 16/00Z runs have started to arrive. Basically we just have
the 00Z HRRR and the 00Z NAMs. The HRRR continues to be a bit more
south with everything than the NAMs. The NAM runs are similar to
the 15/12Z runs, though both the 12km and 3km NAM have a bit more
QPF in their latest runs than the 12Z runs. The 00Z NAM
precipitation shields look similar to earlier runs, though maybe a
tad bit to the west. The same forecast conundrums exist this
evening as it did this afternoon. First, there is still going to be
a sharp west/northwest side gradient on the back edge of the
precipitation (likely just east of I-65). Second, the question of
the warm nose aloft coming in and keeping things more of a wintry
mix of snow/sleet/freezing rain vs. plain snow. The NAM runs
continue to show that wintry mix in the morning, but still turn it
to all snow in the afternoon. Again, the question here is how
quick. The 3km NAM seems a bit quicker, based on looking at the
actual model soundings vs. model derived p-type.
At this juncture, we are going to wait and see what the GFS and Euro
offer on one more run. While the NAM/GFS/Euro all show plenty of
wintry precipitation and decent amounts, one has to also take into
account the possibility of the HRRR being correct as well (with its
lesser amounts). Should the 00Z NAM trends hold into the 06Z runs
and agree with the GFS and Euro, I would tend to think that the
current warning may need to be extended a row of counties to the
west or so with the next forecast update. The back edge of the
advisory area, in the I-65 corridor still looks decent at this time
based on the current data.
&&
.Short Term...(This evening through Sunday Night)
Issued at 345 PM EST Sat Jan 15 2022
...Winter Storm Looking Increasingly Likely For Southern/Eastern
KY...
A closed upper low will pivot from the eastern Red River Valley this
afternoon through the lower Mississippi River Valley tonight. From
there, this feature will turn northeastward up the Appalachian spine
to the mid Atlantic through Sunday and Sunday night. The
precipitation shield associated with this system is currently along
and south of a line from Poplar Bluff, MO over to Nashville, TN, and
as the system pivots across the south tonight, it should largely
stay south of our CWA. As we move into the pre-dawn hours and
especially around sunrise the northern edge of the precipitation
shield will start to work into our southern counties along the KY/TN
border. P-type is expected to start out as snow or a light mix,
however as we go through Sunday morning a warm nose is expected to
strengthen over southern and eastern portions of the CWA. This will
make for a messy mix across southern KY through Sunday morning.
As we move into the afternoon and evening, p-type is expected to
quickly change to all snow as a very nice deformation zone to the NW
of the upper level low pivots over our area. Here, expect solid
bands of moderate to briefly heavy snow capable of strong rates
thanks to a frontogenetical component and saturation up through the
DGZ. Some of the banding could produce 1" to briefly 2" per hour
rates in the warning area. Some of the data suggests that the band
could really get going up through the I-75 corridor along a line
roughly from Richmond up through the Lexington and Winchester area.
Will continue to message 3 to 6" in the Warning area, with locally
higher amounts, but think this area will have the best chance to
produce totals closer to the higher end of the range.
The event ends late Sunday evening/night as light snow as the
deformation zone quickly lifts off to the NE. However, another quick
hitting shortwave will dive through the area and bring some
scattered snow showers with light accums into Monday. See more about
that in the long term.
Going with 1 to 3" of mostly snow in the Advisory area. Again, some
sleet and/or freezing rain could mix in to make impacts a bit more
of a concern.
P-Type:
The warm nose across the south and east CWA is going to make p-type
a challenge as most data agrees with it falling somewhere in the
+0.5 to 1C, but through a fairly deep layer. Below the warm nose,
there does appear to be a sufficient layer for re-freezing which
would lend more to sleet, however some models have been quite
bullish on freezing rain prospects, likely due to the depth of the
subtle warm nose. Given that surface temps are expected to be
marginal for any strong ice accretion, and increasing precipitation
rates would also limit the efficiency of ice accretion, will
downplay but not totally ignore the ice potential. Mentioning a
glaze to less than a tenth of an inch of ice in most of the Advisory
and Warning areas. Thanks to WPC for the collab on the ice potential.
Confidence:
Confidence will remain low to medium for timing, p-type, and amounts
due to several factors. 1.) model consistency and spread has
continued to make things challenging for this storm due to the
complexity of its evolution and track. 2.) the warm nose could play
spoiler to larger snow totals, however more sleet could make impacts
just as significant. So, felt the Warning was justified even if it
is on the low end of significant. 3.) Surface temps are also in
question and look somewhat marginal through the event for max
accumulation. This was one of the reasons freezing rain was given
more credit, and it could also be a reason for snow amounts lower
than the current forecast. 4.) The tight gradient will also make for
a close call on who sees more wintry impacts versus others. Just
like the last event, a small shift in the track could make for a
worsening or improving forecast for areas along the border of the
Warning/Advisory. Stay up to date of the latest forecasts.
Boom or Bust?:
There still remains enough uncertainty that this could go either
way. Some data still shows the deformation band farther NW, which
would bring the need for warning level impacts also farther NW. On
the other hand, some of the data also points to simply Advisory
level impacts across our far eastern CWA only. Like the previous
forecast, this one takes a blend of the two scenarios, if not
slightly leaning toward the more pessimistic/wintry outcome.
Bottom Line:
Pay attention to the latest forecasts through tonight and tomorrow
as significant changes could still occur, especially along the
gradient between Warning/Advisory.
.Long Term...(Monday through Saturday)
Issued at 305 PM EST Sat Jan 15 2022
Large upper low and associated winter weather will be lifting off to
the northeast Monday morning, but another quick hitting shortwave
will be moving into the region. The result looks to be some light
snow showers for Monday morning and early afternoon, mainly focused
east of I-65. Our atmospheric column will certainly be cold enough
thanks to deep NW flow and CAA, so precip type is expected to be all
snow. Due to the cold temperature profiles, snow to liquid ratios
look to be higher across the Bluegrass, where little QPF could
result in some light snow accumulations. NW winds will be breezy
through the day as well in response to a tight pressure gradient and
40kt winds at 850mb, which will contribute to holding temps in the
30s across the region.
Low level ridging and broad sfc high centered across the Gulf States
will spread northward on Tuesday. We`ll remain dry for the day, but
model soundings suggest some clouds to stick around through the day.
Southerly winds will help temps reach the 40s, which is where temps
should be for this time of year. To our northwest, another upper
shortwave and associated low pressure system will be riding along
the Canadian/US border. A secondary sfc low looks to develop off the
Rockies by Tuesday morning, and is expected to track across the
TX/OK region by Tuesday night.
Our next rain chances come Wednesday as a cold front associated with
the aforementioned northern sfc low approaches the region. As the
primary sfc low tracks across the Great Lakes, sfc analysis
Wednesday morning should reveal the cold front cutting through IN/IL
and down through the Ozarks and connecting to the secondary sfc low
over the ArkLaTex region. Rain showers are most possible through the
Wednesday afternoon and evening time frame, with temperatures warm
enough to support liquid precip through most of the day. Cold air
just behind the front could interact with some lingering precip, so
we could see some wintry precip along the frontal passage Wednesday
evening. Regardless, wintry precip appears to be short-lived and
rather light, so no snow accumulations are expected at this time. We
trend colder for Thursday and into the weekend as northerly flow
arrives, with temps currently forecast in the 30s for Thu-Sat.
&&
.Aviation...(00Z TAF Issuance)
Issued at 619 PM EST Sat Jan 15 2022
IMPACTS:
- VFR conditions this evening and into the overnight period
- Wintry precip expected at KBWG/KLEX and possibly KSDF
- IFR conditions possible late tomorrow afternoon in SN at KLEX
DISCUSSION:
Conditions have improved to VFR across the region and should remain
that way this evening and into the overnight hours with a a light
northeasterly wind. Cigs will fall at KBWG late tonight as wintry
precipitation moves northeastward from TN. This activity will also
move into the KLEX area by 16/15-16Z. Depending on back edge of
precipitation shield, KSDF could see some light snows, but it may be
a close call and KSDF could remain precip free. Did go ahead and
drop conditions to IFR for KLEX tomorrow afternoon/eve as snow works
through the region.
CONFIDENCE:
Medium confidence on all elements.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...Winter Weather Advisory from 11 AM EST /10 AM CST/ Sunday to 3
AM EST /2 AM CST/ Monday for KYZ034>040-045>047-053-054-
062>065.
Winter Storm Warning from 6 AM EST /5 AM CST/ Sunday to 1 AM EST
/midnight CST/ Monday for KYZ055>057-066-067-074-076>078.
Winter Weather Advisory from midnight tonight to midnight CST
Sunday night for KYZ070-071.
Winter Storm Warning from midnight tonight to midnight CST
Sunday night for KYZ072-073-075-081-082.
Winter Storm Warning from 11 AM Sunday to 3 AM EST Monday for
KYZ041>043-048-049.
&&
$$
Update.......MJ
Short Term...BJS
Long Term....CJP
Aviation.....MJ
Area Forecast Discussion
National Weather Service Paducah KY
543 PM CST Sat Jan 15 2022
.UPDATE...
Issued at 533 PM CST Sat Jan 15 2022
Updated aviation discussion for 00z TAFs.
&&
.SHORT TERM...(Tonight through Monday night)
Issued at 326 PM CST Sat Jan 15 2022
Fourth day in a row looking at this system and its still not clear
whether or not the northern edge of the deformation zone
precipitation will reach west Kentucky. The 12Z HREF, including
the latest HRRR keep the precipitation well south and southeast of
the area late tonight and Sunday. Unfortunately, the larger-scale
models are still pulling precipitation up into west Kentucky. We
are still forecasting temperatures to drop to or just below
freezing along the Tennessee border, but it is just barely below
and would not be surprising if it was a bit warmer, given how warm
we got in our eastern areas today.
The new official forecast snowfall has an inch in southeast
Calloway county and less than an inch in southern portions of
Trigg, Christian and Todd counties. Just to muddy the works, some
models are trying to generate freezing rain instead of snow, which
doesn`t seem terribly likely. We have chosen to not indicate any
ice accumulation, but there are some patches of freezing rain over
the Pennyrile mentioned in the grids. Given the uncertainty we
will continue with the Special Weather Statement for those areas
and will issue an Advisory if an when it becomes necessary.
Now back to the west. The upper low is finally starting to inch
eastward over northeast Texas and as such the deformation zone is
coming together over southern portions of southeast Missouri late
this afternoon. Mosaic radar has shown an obvious northward surge
of moisture that will terminate in southeast Missouri, so am a
bit concerned it may take a while longer for the precipitation to
shift south of the area this evening. Wouldn`t be surprised if
southern portions of the Advisory get another inch or two before
it is done. As such we have extended the existing Advisory until 9
PM CST. In addition, we have added Butler County in order to
capture all of the higher terrain, which seemed to make the
difference this afternoon.
Very strong north winds will develop through this evening mainly
over the delta region of southeast Missouri. Gusts 25 to 35 mph
will be possible. This should lead to strong drying where the
pavement is just wet, which would preclude black ice. Where there
is appreciable accumulation on roads it will likely go from slushy
to frozen fairly quickly late this evening. Lows will be in the
low to mid 20s out there, so even treated roads may become slick
by morning.
For Sunday, there will be quite a bit of sunshine over most of the
region and with little snowpack, temperatures should reach the
upper 30s to lower 40s. North winds will continue at around 10kts
with some gusts, so it will feel quite cool.
Sunday night a second storm system will slide southeast into the
Ohio Valley, right on the heels of our current system. This will
lead to an increase in clouds especially east of the Mississippi,
and may bring some light snow to the northern portions of southern
Illinois and the Tri State in the 03Z to 09Z time frame. The NAM
is the most excited about precipitation while the GFS and ECMWF
are not. We went with the collective of surrounding offices in
adding PoPs for this system. Northwest winds will crank up in the
wake of this system for Monday, leading to another blustery day.
.LONG TERM...(Tuesday through Saturday)
Issued at 326 PM CST Sat Jan 15 2022
The jet stream pattern will remain unchanged next week. The mean
long wave trough axis will stay positioned over the eastern states
while ridging persists in the West. Temperatures will briefly
moderate Tuesday ahead of a reinforcing arctic cold front
accompanying a 500 mb shortwave in the northwest flow. Some rain is
expected with this mid-week cold front, but amounts will be limited
by the short window for pre-frontal moisture return.
Much colder air will arrive Wednesday night, possibly causing a
brief transition to snow before ending. Wind chills early Thursday
morning will likely be down in the single digits for all but the
Pennyrile region of west KY. Highs Thursday and Friday will be sub-
freezing, and wind chills will likely not rise out of the teens
Thursday. With a 1040 mb high approaching, the dry arctic air mass
is unlikely to yield any snow. However, the ensemble means indicate
a pronounced 500 mb shortwave passage Thursday or Thursday night.
The forecast will include a period of increasing cloudiness Thursday
night, but pops will be kept under 20 percent.
After the surface high passes overhead Friday, another short period
of moderating temps is expected Saturday ahead of another arctic
front. The forecast will be kept dry Saturday, though clouds will be
on the increase.
&&
.AVIATION...
Issued at 533 PM CST Sat Jan 15 2022
VFR cigs are expected at all terminals through the period.
However, MVFR cigs will persist across our southern counties from
KPOF to KHOP before scattering out late tonight through midday
Sunday. Any -RA and -SN should remain confined to this corridor as
well. Gusty northeast winds will continue this evening with gusts
as high as 25-30 kts possible, particularly south of KCGI-KPAH
terminals. Winds gradually decrease overnight as they turn more
northerly and eventually NW on Sunday. Gusts in the 15-20 kt range
will be possible again through much of the region on Sunday.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...Winter Weather Advisory until 9 PM CST this evening for MOZ100-
107>109.
IN...None.
KY...None.
&&
$$
UPDATE...SP
SHORT TERM...DRS
LONG TERM...MY
AVIATION...SP